Oxygen (O2) Calibration Gas

**BUY NOW** | PORTACAL® Oxygen calibration gas. Oxygen deficiency is the leading cause of confined space injuries and fatalities. As defined by OSHA, any area that contains less than 19.5% oxygen is O2 deficient. Normal atmospheres contain between 20.8 and 21% oxygen. Oxygen above the normal level of 21% increases the flammability range of combustible gases or material and causes them to burn violently.